It is generally understood that agricultural crops such as fruits and vegetables are most preferably cooled as quickly as possible after harvest to inhibit premature ripening and to otherwise minimize post harvest spoilage. Various methods for cooling fruits and vegetables following harvest include the use of large room coolers wherein the perishable products are placed and their temperature drawn down to a desired level and relative humidity, vacuum cooling (generally for leafy vegetables and the like), subjecting the products to a shower of relatively cold water, and forced air cooling such as shown in U.S. Pat. No. 5,054,291, which issued to T. Davis et al. Generally, in these various methods for post harvest cooling, the products must be repackaged and/or otherwise removed from the cooling room or chamber for transportation and/or ripening procedures.
It has often been desirable to delay ripening of the perishable products until initial shipping had been completed, as most ripening facilities were not located in the tropics. In many cases, tropical fruit or the like was first cooled in a manner similar to that described above, then repackaged for shipment to remote markets in refrigerated shipping containers, and thereafter placed in ripening rooms for completion of the ripening process prior to final shipment to the retail market. U.S. Pat. No. 5,041,298 which issued to G. Wallace et al., illustrates a ripening room type apparatus which includes an atmosphere controlling means for applying controlled atmosphere to appropriately stacked crates of product therewithin. As discussed in this reference, economic considerations require such ripening rooms to be of relatively large size, and Wallace et al. direct their invention to the provision of a particular frame arrangement to allow selective stacking of the crates with particular interstitial volumes therebetween for facilitating air movement for ripening procedures.
U.S. Pat. No. 4,845,958, which issued to A. Senda et al. pertains to a refrigeration chamber which is designed to remove certain atmospheric constituents such as ethylene and nitrogen triethylamine, which have been found to cause increasingly rapid maturation, ripening and aging of perishable products. It is recognized in this reference that low temperature alone cannot prevent the further ripening of products, and means must be provided to remove or absorb elements which augment the ripening process. Senda et al. contemplate the use of adsorption materials located within a filtering mechanism for removing harmful aging substances as part of the air circulation within the chamber.
Conventionally, unripened fruit and vegetables have been shipped in refrigerated containers from shipping warehouses for freshly harvested products, and, following shipment, placed in a ripening facility for holding the products until proper maturation. In addition to the references discussed above, there is a significant amount of knowledge and prior art in the industry showing the use of controlled atmosphere arrangements for delaying ripening of product from harvest to the ripening facilities. For example, U.S. Pat. Nos. 5,152,966 and 4,817,391, which issued to E. Roe et al., describe devices for producing controlled atmosphere in an area in which perishable products are held prior to desired ripening procedures. Particularly, atmospheres of reduced oxygen and lowered temperature are discussed in these references, and membrane separation technology for reducing and separating unwanted constituents of the recycled atmosphere is illustrated. U.S. Pat. No. 4,824,685, which issued to M. Bianco, similarly describes the conventional ripening rooms wherein ethylene is dispersed at a preselected time to facilitate and speed up the ripening process. This particular reference also describes a preferred frame structure arranged within a ripening chamber to enable flow of the atmosphere through interstitial volume between rows of boxed products, and to allow more freedom in the placement and removal of palletized products into and out of the ripening chamber.
Similarly, U.S. Pat. No. 4,764,389, which issued to L. LaBarge, discusses a method of accelerating fruit ripening and respiration by providing a continuous in-flow of air and ethylene gas in a ripening chamber. In the industry, the continuous flow of gases within a ripening chamber, such as contemplated in the LaBarge patent, is utilized for a variety of products and processes for accelerating the ripening process just prior to release of perishable products into the retail trade. For example, palletized ripening for bananas and other perishable products has been provided at ripening facilities for use with semi-trailer loads of products which are backed into modular ripening units. Particularly, ripening equipment of this type can be obtained from Modular Ripening Company, Inc., (Virginia Beach, Va.), wherein a modular ripening facility includes a plurality of trailer docks, whereby semi-trailer loads of products are backed into the docks (with the truck doors open), and thereafter the ripening equipment provides a continuous flow of refrigerated atmosphere to the trailer to facilitate rapid ripening of the products therewithin.
Consequently, it can be seen that many procedures and structures have been developed in an attempt to provide the ability to ship unripened perishable products from the tropics and similar harvesting locations in refrigerated and controlled atmosphere containers, thereafter unloading the containers and shipping the product to ripening facilities, implementing rapid ripening processes, and then shipping the ripe products to retail market. Problems still remain, however, in the uniform and reliable control of ripening of the products such that all products in a particular load will be delivered with consistent color, maturity, and quality. Current procedures for shipping unripened products for bulk ripening prior to retail distribution cannot provide uniform and consistent quality (e.g., fruit temperature) and ripeness (e.g., color) characteristics, and slight changes and/or problems in the transportation or delivery schedules can result in relatively costly quality control problems.
Additionally, as can be appreciated, conventional shipping, unloading, ripening, and final transportation arrangements require substantial investments of labor and capital. All of these factors also add numerous variables to the product quality control concerns, further complicating and undermining the ability to maintain consistently high quality and uniform ripeness and color characteristics of the perishable products. It often takes 10-14 days from harvest for delivery of the product to the ripener, then an additional 4-7 days for ripening and delivery of product to retail merchants. Moreover, relatively slight delays in shipping and/or delivery schedules can result in major consequences with respect to fruit quality and spoilage.